7. A college campus plans to provide awnings above its sidewalks to shelter students from the rain as they walk from the parking lot and between buildings. To save money, awnings will not be placed over all the sidewalks shown in the figure. Just enough awnings will be placed over a select number of sidewalks to ensure that students walking from building to building will be able to do so without getting wet. Classroom Building 125 feet 155 feet Library 135 feet 115 feet 155 feet Gym a) Use a weighted graph to model the given map. Represent buildings as vertices, sidewalks as edges and sidewalk lengths as weights. Administration 55 feet Cafeteria 135 feet Parking Lot 215 feet b) Use Kruskal's algorithm to find a minimum spanning tree that allows students to move between the parking lot and any building shown without getting wet. c) What is the total length of the sidewalk that needs to be sheltered by awnings?